KR20030025798A - air path switching apparatus - Google Patents

Abstract

PURPOSE: To provide a directional control device for air flow capable of controlling deformation due to contraction after forming and preventing air leak to other than an airflow outlet part to which air supply is expected. CONSTITUTION: This device is constituted of a rotor 71 having an airflow inlet part R0 in the rotation shaft direction and an airflow outlet part R1 communicated with the airflow inlet part R0 in the circumferential direction, a housing 72 rotatably containing the rotor 71 and having an airflow inlet part H0 in the rotation shaft direction and plural airflow outlet parts H1-H5 in the circumferential direction and a motor rotating/driving the rotor 71 such that the airflow outlet part R1 is communicated with any one of the airflow outlet parts of the housing 71. Outer peripheral side of the rotor contacting inner peripheral side of the housing 72 is formed with thin-walled.

Description

Air flow channel switching device {air path switching apparatus}

The present invention is used, for example, in a water treatment system or the like having a plurality of tanks for storing, clogging and purifying a drainage, including a food waste crushed product, in a disposer of a sink. The present invention relates to an air flow path switching device for switching air flow paths necessary for the treatment of aeration (aeration and sedimentation promotion) and transfer between each tank (air lift).

In the water treatment system disclosed in Japanese Patent Application Laid-Open No. 2000-588 (C02F 3/12) by the applicant of the present application, about one air inlet in which air sent from there to the air supply means (blower, etc.) is introduced. The air flow path switching means having a plurality of air outlets which can be switched and controlled is connected to supply air to each tank, and the blower can be treated by one.

For example, FIG. 6 is a system configuration diagram showing an example of a water treatment system for purifying drainage water from a disposer and discharged to a sewer. The air is switched from one blower to six flow paths for use. In addition, the piping shown by the solid line has shown the flow of a liquid (solid liquid mixture), and the piping shown by the broken line has shown the flow of air.

In the water treatment system, the wastewater containing the food waste crushed from a disposer, not shown, is once stored in the flow adjusting tank 10, and the precipitate is introduced into the solid-liquid separator 20 from the air lift pipe 11. The solids and liquids are separated, the liquids are returned to the flow rate adjustment tank 10, and the solids are fed into the conposting (composting) device 30 to compost by organic decomposition by microorganisms. In addition, the suspended liquid in the flow rate adjustment tank 10 is transferred from the air lift pipe 12 to the aeration tank 40, and the organic matter component is decomposed by the microorganism by the aeration treatment. Then, the floating liquid of the aeration tank 40 is naturally dropped in the sedimentation separation tank 50 communicating with the upper portion to precipitate mud, and the floating liquid is discharged into the sewerage, and the precipitated mud is airlift pipe ( In 51), the flow is adjusted to the flow rate adjustment tank 10 at an initial stage.

In the water treatment system, one blower (60) is used, and the flow rate adjusting tank (10) and the aeration tank (40) through an air flow channel switching device (70) for converting air from the blower (60) into respective flow paths. ), And is supplied to the sedimentation tank (50).

In addition, the air flow path switching device 70 has an air inlet R0 in the direction of the rotation axis, and has a rotor 71 and a rotor having an air outlet R1 communicating with the air inlet R0 in the circumferential direction. The housing 71 freely rotates, has an air inlet H0 in its rotation axis direction, has six air outlets H1 to H6 in the circumferential direction, and an air outlet of the rotor 71. R1 is constituted by a motor (not shown) which rotates so as to communicate with one of the air outlets H1 to H6 of the housing 72.

Air pipes 81 to 86, each of which is indicated by broken lines, are connected to the air outlets H1 to H6 of the air flow path switching device 70, and the tip of the air pipe 81 is piped to the bottom of the aeration tank 40. The air diffuser pipe is connected, and the tip of the air pipe 82 is connected to the lower part of the air lift pipe 12 for airlifting the floating liquid of the flow rate adjustment tank 10, The front end is connected to the lower part of the air lift pipe 11 for airlifting the sediment of the flow adjusting tank 10, and the front end of the air pipe 84 is the air lift pipe for airlifting the sediment of the sedimentation separation tank 50 ( 51) connected to the lower part, the tip of the air pipe 85 is piped to the lower part of the flow rate adjustment tank 10, and the diffuser 85a is connected, and the tip of the air pipe 86 is connected to the settling separation tank 50. The diffuser 86a is connected to the lower part by piping.

The check valve 90 is attached to the air pipes 81, 85, and 86 to which the diffusers 81a, 85a, and 86a are connected among the air pipes 81 to 86, respectively.

In addition, although not shown, a control unit comprising a microcomputer or the like for controlling the entire water treatment system, and an operation display unit for displaying the status of various operations and abnormalities are provided, and the blower 60 and the air flow path described above are provided. The switching device 70 is also controlled by the control unit.

As the air flow path switching device 70, for example, the one having the configuration as shown in FIG. 7 has already been proposed by the present applicant (Japanese Patent Application No. 2000-384686).

The air flow path switching device 70 forms an inner surface shape of the housing 72 in a substantially bowl shape, and forms the rotor 71 in an approximately top shape corresponding to the inner surface shape of the housing 72. will be. That is, the angle formed by the substantially inclined inner surface 72b of the housing 72 and the angle formed by the substantially inclined side inclined surface 71b of the rotor 71 are formed to be the same angle. Openings reaching the respective air outlets H1 to H5 (only H2 and H5 in the drawing) are formed at the inner inclined surface 72b of the housing 72 at equal intervals, and the side inclined surface 71b of the rotor 71 is formed. An air outlet R1 corresponding to the opening is formed in the opening. The air inlet hole H0 of the housing 72 is installed with a housing cover 72c that covers the upper opening of the approximately bowl shape, and after the rotor 71 is accommodated in the approximately bowl-shaped space of the housing 72, the cover ( 72c).

Moreover, each diameter is set so that the rotating shaft 71d of the rotor 71 may penetrate the through-hole 72d formed in the bottom part of the housing 72 leisurely.

In addition, since the rotor shaft 71d and the motor shaft 73a of the rotor 71 are connected in a universal joint structure in which the rotor 71 is movable in the motor axial direction (thrust direction), the motor The cross motor shaft 73e is provided at 73, and the cross groove 71e to which the cross motor shaft 73e is fitted is the height of the cross motor shaft 73e at the rotation shaft 71d of the rotor 71. It is formed deeper, and load is not applied to the cross motor shaft 73e.

In addition, a positioning rotary plate 75 is mounted on the rotary shaft 71d of the rotor 71, and positioning is performed at intervals corresponding to the air outlets H1 to H5 around the positioning rotary plate 75. A dragon hole (not shown) is formed, and one of the positioning holes is formed so as to be distinguishable from the other for the current position recognition. Further, the photosensor 76 is mounted so as to be positioned above and below the positioning rotary plate 75. The photosensor 76 and the positioning rotary plate 75 allow the rotor 71 to be positioned. The air outlet R1 is configured to be positioned at any of the air outlets H1 to H5 of the housing 72.

The air flow path switching device 70 receives air from the blower 60 described above at the air inlet HO of the housing cover 72c and passes through the rotor 71 to the housing 72 selected by the rotor 71. It is composed of the air discharged to either side of the air outlet. At this time, air pressure is applied to the rotor 71 and the rotor 71 is pushed downward so that the side inclined surface 71b of the rotor 71 is pressed against the inner inclined surface 72b of the housing 72. Iii) to prevent air leakage.

However, since the air blown from the blower 60 is heated by the blower 60, the heated air is blown from the blower 60 to the air flow path switching device 70. Here, when the blower 60 contains a large amount of moisture in the air blown in (for example, in the case of the structure in which the blower 60 blows in air from the outside of the water treatment apparatus, the humidity in the rainy weather) In the case of the configuration blown in from the outside air or the inside of the water treatment apparatus, the steam generated in each tank or the like inside the apparatus) and the air from the blower 60 become high temperature and high humidity.

When the high temperature and high humidity air flows into the air flow channel switching device 70 at room temperature, the gap between the rotor 71 and the housing cover 72c, the inclined surface 71b of the rotor 71 and the housing ( Condensation water is generated between the internal inclined surface 72b of 72), and the water droplet W flows down and attaches to the photosensor 76 or the motor 73, which is an electrical component immediately below, and the air flow path. The malfunction or failure of the switching device 70 may occur, or the rotor 71 may be in close contact with the housing 72 due to the surface tension effect of water, and thus switching to the air flow path may not be performed.

Further, in the above configuration, since the blower 60 and the air flow path switching device 70 are directly connected, the noise (including the low sound wave vibration sound) generated by the blower 60 passes through the air flow path switching device 70. In addition, it spreads to each pipe and caused noise of the whole water treatment apparatus. In order to prevent the noise, if the soundproofing measures are performed for each pipe, the number of parts for the soundproofing measures is increased and the installation space is increased, thereby increasing the water treatment apparatus and increasing and decreasing the cost.

Therefore, the applicant of the present application proposes a new one as shown in Fig. 8 in which condensation measures or sound insulation measures are implemented to eliminate imperfections as described above (Japanese Patent Application No. 2001-85127).

Here, first, the motor 73, the photosensor 76, etc. which are electric components of the air flow path switching device 70 are arranged above the rotor 71 and the housing 72. That is, the arrangement is such that the up and down of the air flow path switching device 70 shown in FIG. 7 is reversed. Even in this configuration, when the blower 60 shown in FIG. 6 is driven and the air is started, the rotor 71 floats upward in opposition to gravity due to the air pressure of the air blower. The side inclined surface 71b of the rotor 71 comes into contact with the inner inclined surface 72b so that no air leakage occurs.

Then, between the blower 60 and the air flow path switching device 70, a cylindrical heat exchanger chamber 100 having a large volume which performs a heat exchange function and a noise function is provided, and the bottom surface 101 is switched to air oil. It was comprised so that it might become integral with the upper wall surface of the electrical component chamber 78 of the apparatus 70. As shown in FIG. In the heat exchange chamber 100, a heat exchange plate 104 is formed between the inlet 102 and the outlet 103 of the air from the blower 60 so as to alternately communicate so that the contact area of the inlet air is increased. .

The bottom surface 101 of the heat exchange chamber 100 is formed of an inclined surface descending toward the discharge port 103, and the heat exchange plate 104 also collects condensed water by tilting the open end side toward the discharge port 103 direction. It is configured to be guided to the reservoir 120 through the pipe 110 continued downward from the outlet 103. In addition, the reservoir 120 is provided with a drain valve 130, and is configured to be drainable to either tank of the water treatment apparatus. The pipe 110 branches from the middle to the horizontal direction and is connected to an air inlet H0 formed in the housing cover 72c of the air flow channel switching device 70.

In the above configuration, the air blown from the blower 60 passes through the heat exchange chamber 100, and then, is sent to the air inlet hole H0 of the air flow channel switching device 70 and is rotated through the rotor 71. The air is discharged to either one of the air outlets of the housing 72 selected by the electrons 71 (the air outlet H5 in the drawing).

With such a configuration, when the water treatment apparatus is installed outdoors during a condition where condensation is easy, for example, during winter, when the ambient temperature where the heat exchange chamber 100 and the air flow channel switching device 70 are installed is low, When the high temperature and high humidity air sent from the 60 passes through the heat exchange chamber 100, the temperature is lowered and extra moisture condenses when it becomes the room temperature and humidity air, and the inclined bottom surface 101 of the heat exchange chamber 100 is exposed. Gathered in the reservoir 120 by.

In addition, since the electrical component chamber 78 of the air flow channel switching device 70 is adjacent to the heat exchange chamber 100 by sandwiching a wall, heat is directly transferred from the heat exchange chamber 100 to warm it. As a result, the temperature of the air from the blower 60 decreases while passing through the heat exchange chamber 100, and the air at the time of entering the air flow path switching device 70 is the air flow path switching device 70 and the electrical component room. Next, the temperature is substantially the same as that of the motor 73 and the photosensor 76, and as a result, no dew condensation occurs inside the air flow path switching device 70.

In addition, even if condensation water is generated in the housing 72 of the air flow path switching device 70 due to some cause (such as when the air flow path switching device 70 is not sufficiently warmed), the upper part of the electrical component chamber 78 As shown in Fig. 8 (c) without reaching), the water droplets w are returned to the air inlet port H0 side of the air flow channel switching device 70 and are sent to the storage unit 120 as before.

The reservoir 120 is provided with a manual drain valve 130 for periodically draining the remaining water, and when the valve 130 is opened, water can be drained to any one of the tanks in the water treatment apparatus. It can prevent the discharge.

In addition, the valve 130 is opened and drained periodically when the blower 60 is stopped by using the automatic operation so as not to overlap with the time to send to each tank, thereby affecting the control of the water treatment system. You can also think about automating it so far.

In addition, since the heat exchange chamber 100 is formed in a structure having a muffler effect to silence the noise (including the low frequency vibration sound) of the blower 60, an air flow path switching device. Before entering 70, noise can be generated, and as a result, it is not necessary to install the soundproofing device for each pipe leading from the air flow path switching device 70, so that the soundproofing measures can be simplified, and the required installation space of the parts can be reduced. It becomes small and the size of a water treatment apparatus can be miniaturized, and a cost reduction effect is also acquired.

By the way, when the rotor 71 as described above is produced by cutting, there is no problem, but when molded into a resin using a mold for mass production or the like, the resin heated during molding shrinks when it returns to room temperature. Thus, as shown in Fig. 9A, the shape of the two-dot chain line, which is a shape that is supposed to be present, does not become a shape, and so-called off occurs to deform into a shape in which the side slopes 71b and the like sink. When this rotor 71 is assembled to the housing 72, as shown in FIG. 9 (b), between the side inclined surface 71b of the rotor 71 and the internal inclined surface 72b of the housing 72. Since a gap is generated in the air gap, a part of the air flowing from the air inlet hole H0 of the housing 72 flows to a route or the like indicated by the dotted line arrow, so that the air leak is not made except for the air outlet port (H5 in the figure). It is generated.

Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide an air flow path switching device capable of preventing air leakage other than the air outlet portion to be depressed by suppressing deformation caused by shrinkage after molding. will be.

In order to achieve the above object, the present invention, a rotor having an air inlet in the rotation axis direction, the air outlet communicating with the air inlet portion in the circumferential direction, the rotor is free to receive the rotation of the rotation shaft A housing having an air inlet in a direction and having a plurality of air outlets in the circumferential direction, and a motor for rotating the rotor so that the air outlet communicates with one of the air outlets of the housing. It is characterized in that the outer peripheral side of the rotor in contact with the inner peripheral side is formed thin.

Specifically, the rotor is molded into an approximately umbrella shape, and the inner surface shape of the housing corresponds to the outer surface shape of the rotor.

In addition, the angle formed by the side inclined surface of the rotor is characterized in that the larger than the angle formed by the inclined surface of the housing.

In addition, it is characterized in that the thickness of the side inclined surface of the rotor is set to be thinner by a large diameter portion.

In addition, the rotor is formed by a flexible material.

In addition, the inner periphery of the housing is characterized in that the molded thin.

BRIEF DESCRIPTION OF THE DRAWINGS It is a principal part structure diagram of one Embodiment of this invention, (a) is a top view, (b) is a longitudinal cross-sectional view, (c) is a figure which shows the principal part seen from the Y direction at the arrow of (b).

Fig. 2 is a road showing the rotor single body of the embodiment, (a) is a top view, (b) is a longitudinal sectional view, and (c) is a bottom view.

3 is a longitudinal sectional view of a rotor in which a side inclined surface is formed thinly, leaving a tubular portion constituting a rotation shaft and an air inlet in the conventional rotor.

It is a principal part structure diagram which shows another embodiment of this invention, (a) is a longitudinal cross-sectional view of a housing | casing single body, (b) is a longitudinal cross-sectional view of a rotor single body.

Fig. 5 is a longitudinal sectional view after assembly of the housing and the rotor shown in Fig. 4 (a) shows a state when no air is fed, and (b) shows a state when air is fed.

6 is a road showing an example of a water treatment system to which an air flow path switching device according to the present invention is applied, (a) is a system configuration diagram, and (b) shows a conventional example of the air flow path switching device. It is a transverse cross section.

7 is a longitudinal cross-sectional view showing an example of an air flow path switching device used in the water treatment system as described above.

8 is similarly a road showing an example of an air flow path switching device on which condensation measures are taken, (a) is a top view, (b) is a cross-sectional view of AA of (a), and (c) is the cause of some cause This is a longitudinal cross-sectional view for explaining the case where dew condensation occurs.

Fig. 9 is a longitudinal sectional view of a rotor unit in which an off occurs due to shrinkage after molding, and (b) is a longitudinal sectional view of an air flow path switching device incorporating the rotor.

Explanation of reference numbers indicating major parts

10: flow rate adjustment tank 20: solid-liquid separation device

30: postpost device

40: aeration tank

50: sedimentation separation tank 60: blower

70: air flow path switching device 71: rotor

71b: side slope 71 g: approximately Y-shaped rib

72: housing

72b: inner inclined surface 72c: housing cover

72g: bearing part

R0, H0: Air inlet 73: Motor

R1, H1 to H6: Air outlet 75: Rotating plate for positioning

76: photosensor

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail with reference to drawings.

1 and 2 are schematic diagrams showing the main parts of one embodiment of the present invention, and the same reference numerals denote the same or corresponding parts.

In the present embodiment, the rotor 71 of the air flow channel switching device 70 is shaped like an umbrella, and the thickness t1 of the rotor 71 is made thin. In addition, a conventional rotor ( 공기 which protrudes downward from the umbrella-shaped ceiling surface by removing the tubular portion provided as an air inlet R0 of 71) and provided as a rotating shaft of the conventional rotor 71, and replacing the above. 71 g of female ribs are provided, and the diameter (d) of the circumscribed circle c shown by a dashed-dotted line in FIG. 2 (c) in this substantially Y-shaped rib 71 g is the same as the outer diameter of the conventional tubular part. It is set to terminate.

That is, the off by shrinkage after molding described above occurs at a thick place. Therefore, when the rotor 71 is molded into an approximately umbrella shape as shown in Figs. 2A to 2C, the thickness t1 of the rotor 71 becomes thin, so that the side of the rotor 71 becomes thin. The inclined surface 71b does not generate an off due to shrinkage after molding.

In addition, since the conventional tubular portion is left, as shown in Fig. 3, the side inclined surface 71b excluding the portion of the communication path from the tubular air inlet R0 to the air outlet R1 is also thinly formed. Although it can be considered, it is impossible to lose weight of the upper portion 71h of the air outlet R1 by forming in this way, so that the side slopes 71b of the side where the air outlet R1 is formed must be inherently formed. Since it does not become a dotted line, it is impossible to fully prevent air leakage other than the air outlet which you want to send.

Therefore, when molding as shown in Fig. 2 (a) to (c) of the present embodiment, when assembled as shown in Fig. 1, as shown in Fig. 1 (c), the air inlet hole H0 of the housing cover 72c 71 g of substantially U-shaped ribs are seen through it, and the net installation part which is an area | region other than the rib 71g functions as the air inlet hole R0 of the rotor 71. FIG. In addition, the lower side of the rotor 71 is rotatable freely positioned at the bearing portion 72g in which the tip end of the substantially U-shaped rib 71g is formed at the upper portion of the air inlet hole H0 of the housing cover 7c.

As shown in FIG. 1, the assembled air flow path switching device 70 enters from the air inlet hole H0 formed in the air housing cover 72c sent from the blower 60 described above, and the rotor 71 Passes between the ribs of the substantially Y-shaped rib 71g functioning as the air inlet R0, and the side inclined surface 71b of the rotor 71 and the inner inclined surface 72b of the housing 72 are press-contacted by air pressure. Therefore, there is no air leakage and is discharged from one of the air outlets (here, H5) of the housing 72 where the air outlet R1 of the rotor 71 coincides.

In addition, in this embodiment, the housing 72 side shown in FIG. 1 is also shape | molded so that thickness may become thin for the same reason as turning off the rotor 71 of the said technique. As described below, when the rotor 71 is molded from a flexible material such as an elastomer, the housing 71 side can correspond to the conventional one, but the housing 72 is the same as in the present embodiment. By shaping the thinner side to have a smaller thickness, it is possible to reliably prevent air leakage regardless of the molding material of the rotor 71.

Further, even if the rotary shaft 71d on the upper side of the rotor 71 connected to the drive shaft of the motor 73 described above with the universal joint structure is turned off, the problem of air leakage does not occur, but the rectangular fitting groove Since 71i deforms into a drum shape, a fattening portion 71j is formed around the fitting groove 71i for preventing this.

4 and 5 are principal part structural diagrams showing another embodiment of the present invention, and the same reference numerals as the above embodiment indicate the same or corresponding parts.

In the present embodiment, as shown in FIGS. 4A and 4B, the angle β formed by the side sloped surface 71b of the rotor 71 is greater than the angle α formed by the inner sloped surface 72b of the housing 72. Molded to be large, and the side inclined surface 71 of the rotor 71

b) thins the thickness t2 to a large diameter portion (downward direction) so that it is easy to deform, and the thickness t3 of the small diameter portion (joint portion) is also molded into a thin film that can be deformed by air pressure.

When these are assembled as shown in Fig. 5 (a), even if the molding material of the rotor 71 is hard (e.g., a plasma such as plastic), air is drawn from the air inlet hole H0 of the housing 72. When it is sent, the rotor 71 deforms as shown in Fig. 5 (b) by air pressure, and the side inclined surface 71b is press-contacted to the inner inclined surface 72b of the housing 72.

That is, when not sending, as shown in FIG. 5 (a), the large diameter portion of the side inclined surface 71b of the rotor 71 is in contact with the inner inclined surface 72b of the housing 72, and the other portions thereof are separated. When the air is blown, first, the deformation is made from the smallest diameter portion that is in contact with the thinnest portion, and as the rotor 71 rises, the deformation portion gradually moves toward the small diameter portion, and finally the deformation proceeds to the minimum diameter portion, and FIG. 5. As shown in (b), the side inclined surface 71b of the rotor 71 is elastically and smoothly in close contact with the inner inclined surface 72b of the housing 71. Thereby, it is possible to more reliably prevent the air leakage to the air outlet other than the air outlet.

Then, when the air supply is finished, the state of the rotor 71 is returned to the state of Fig. 5 (b) from Fig. 5 (b) by the weight of the rotor 71 or the elasticity of the side inclined surface 71b. It is possible to prevent the overload of the motor (not shown) by being rotated to switch to the air flow as it is in close contact with the inner inclined surface 72b of the housing 71.

By the way, the action described in each embodiment of the above technique is easily formed again by forming the rotor 71 so as to be easily deformed at pneumatic pressure by using a flexible material such as an elastomer (synthetic rubber, etc.) to improve the sealing degree. In this regard, the air leakage preventing performance of the air flow path conversion device is further improved.

According to the present invention as described above, a rotor having an air inlet in the rotational axis direction and having an air outlet in communication with the air inlet, the rotor having a circumferential direction, and freely rotating the rotor, and introducing air in the rotational axis direction. And a motor having a plurality of air outlets in the circumferential direction, and a motor for rotating the rotor so that the air outlets communicate with any one of the air outlets of the housing. By thinly forming the outer circumferential side of the rotor in contact, it is possible to suppress deformation caused by shrinkage after molding of the rotor and to prevent air leakage outside the air outlet portion to be blown.

Specifically, the rotor can be formed into an approximately umbrella shape, and the inner surface shape of the housing can be made to correspond to the outer surface shape of the rotor.

In addition, by setting the angle formed by the side inclined surface of the rotor larger than the angle formed by the inner inclined surface of the housing, the side slope of the rotor is deformed by the air pressure during the air supply to elastically close to the inner slope of the housing Therefore, it is possible to more reliably prevent the air leakage outside the air outlet to be blown.

In addition, by setting the thickness of the side inclined surface of the rotor to be as thin as a large diameter part, the first side is deformed from the thinnest large diameter part and gradually deformed toward the small diameter part, so that the side inclined surface of the rotor moves inside the housing. Gently adhere to the slope.

In addition, by forming the rotor from a flexible material, it is easy to deform at the air pressure and improves the airtightness, whereby the air leakage preventing performance of the air flow channel switching device is further improved.

In addition, by forming the inner peripheral side of the housing thinly, it is possible to suppress deformation due to shrinkage after molding on the housing side, so that air leakage can be reliably prevented regardless of the molding material of the rotor.

Claims (6)

A rotor having an air inlet in the rotational axis direction, the rotor having an air outlet in communication with the air inlet in the circumferential direction, the rotor freely receiving the rotor, and having an air inlet in the rotational axis direction, and a plurality of air in the circumferential direction A housing having an outlet, It is made of a motor for rotating the rotor so that the air outlet portion communicates with the air outlet portion of any one of the housing, And an outer circumferential side of the rotor in contact with the inner circumferential side of the housing. The method of claim 1, Shaping the rotor into an umbrella shape, And an inner surface of the housing corresponds to an outer surface of the rotor. The method of claim 2, And an angle formed by the side slope of the rotor is greater than an angle formed by the inner slope of the housing. The method of claim 3, wherein An air flow path switching device, characterized in that the thickness of the side inclined surface of the rotor is set to be thin as large diameter portion. The method of claim 4, wherein An air flow path switching device, characterized in that the rotor is formed of a flexible material. The method of claim 5, An air flow path switching device, characterized in that the inner peripheral side of the housing is formed thin.